Solve the formula for the indicated variable D=ABC for A

Asegment in the complex plane has a midpoint at 7 – 2i. if the segment has an endpoint at 11 – 3i, what is the other endpoint?

Asap! i'm not good math and i'm lost.

He weights of 2-pound bags of best dog food are approximately normally distributed with a given mean  and standard deviation  according to the empirical rule, what percentage of the bags will have weights within 3 standard deviations of the mean? 47.5%68%95%99.7%